What could be the reason for only one side bottoming out?

Most people have significant a symmetry of their body.
This includes the breast left, typically sitting higher on the chest wall than the right side.
This is true for all people, both men and women.
From most people the left breast sits about half an inch higher than the right side.
For some people it’s slightly less.
If you look at your original before and after pictures, you’ll probably see that the left breast sits higher on your chest wall than the right side.
When surgeons do breast augmentation surgery, they often aiming towards creating symmetrical outcome, and this is often what patients want themselves.
If the left breast sits higher on the chest wall and the surgeon places the implants symmetrically, then they will place the implant lower than the left side.
The reason implants bottom out is because the IMF(infra mammary fold) has been opened or violated.
without including proper before, and after pictures, we can begin to make an assessment.
I am no idea what happened in your case, but my explanation seems plausible, considering that most people, including plastic surgeons are not aware that the left breast sits higher on the chest wall on almost every person in comparison to the right side.
take a look at pictures of naked people, and you’ll see that the left breast almost always sits higher than the right side.
if you want us to make an assessment regarding the outcome of your procedure, then try reposting with a complete set of proper before and after pictures.
if you want proper second opinion, consultation, and schedule that as an in person consultation with other plastic surgeons in your community.
For second opinion, consultations come prepared bringing with you a complete set of proper before and after pictures and copies of your previous operative report.
These are all part of your medical records and you can request them from your previous provider.
Best,
Mats Hagstrom MD